Significant progress has been achieved in the identification of genetic causes for congenital human syndromes. At the same time, mutations in known genes still explain only a small portion of the broad spectrum of human craniofacial phenotypes. This may be due, in part, to screening limitations, since the majority of current genetic screens focus on sequence analysis of the coding region(s) of a gene(s) and, therefore, fail to detect gene deletion(s)/duplication(s) or changes in regulatory elements important in gene function. In addition, the genetic causes for many congenital human conditions are still unknown and thus cannot be evaluated in human patients. In this proposal, we plan to expand genetic studies of craniofacial phenotypes through genome-wide copy number variation analysis. This effort will result in identification of additional mutations (deletions/duplications) associated with known genes and will direct discovery of novel factors, therefore empowering human researchers with new insight into disease mechanisms. Candidate genes will be identified based on their location within a genomic region of interest and functional studies in animal models. Mutation screening in affected individuals will provide additional support for a causative role for the gene in human disease. In this proposal, we plan to utilize our collection of DNA samples from patients with human congenital conditions involving craniofacial anomalies which was already examined for mutations in genes known to play a role in the corresponding phenotypes. Our preliminary analysis of a subset of our sample for copy number variants resulted in identification of numerous alterations involving known genes as well as changes in novel, previously unreported, regions. Therefore, we believe that our study will generate critical data that will lead to the identification of new genetic causes for human craniofacial syndromes and thus will have a high impact in the field of human craniofacial biology. Specifically, we plan to identify genomic regions that are affected in human craniofacial syndromes by copy number variation analysis (Aim 1);evaluate candidate genes associated with these genomic region(s) for their potential role in the syndrome(s) using the zebrafish model (Aim 2);and examine best candidate genes for point mutations in human patient DNA to further confirm/ characterize their role in the corresponding syndromes (Aim 3). PUBLIC HEALTH RELEVANCE: Our project is aimed at identification of the novel genetic causes of human craniofacial syndromes using new genomic screening technology and studies in animal models. The knowledge obtained from this project will provide insight into disease mechanisms(s) and eventually lead to improved diagnosis, genetic counseling and treatment of affected patients and their families.